Denial of tea service

In a “denial of service” attack, a web site is taken down by flooding it with requests (generally by software robots that are pretending to be people) until the site crashes from overload.

I was at lunch today with a group of friends, and most of us ordered tea. It came up in conversation that tea is the most expensive item to serve in a restaurant, in terms of time/effort of the server per dollar collected from the customer (there are people who actually study these things).

And it occurred to me that if you really hated a restaurant, and wanted to take it down, you could just get all your friends to go there and order nothing but tea. Eventually, the restaurant would be overwhelmed by the need to serve all those individual slices of lemon, servings of cream, cups, saucers, spoons and sugar containers, and (if it’s an upscale place) little pots of tea and freshly steeped tea leaves.

I’m not saying anybody should ever do such a thing. My heart goes out to poor overworked restaurant employees everywhere just thinking about such a thing. But I wonder — would it be illegal? Or perhaps more interestingly, would such an act ever be ethically justifiable? More broadly, is a DoS attack purely an on-line phenomenon, or are there in fact real-world examples of pre-internet denial of service attacks?